The following relates generally to wireless communication, and more specifically to enhanced non-access stratum (NAS) security.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems. A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may each be referred to as a user equipment (UE).
A UE, therefore, may participate in communications with a network. Some network communications may be between a UE and a core network, which may include a protocol stack for facilitating the network communications. One functional layer used in the core network protocol stack is a NAS layer. The NAS layer is a set of protocols and is generally used to convey non-radio signaling between a UE and a mobility management entity (MME) for access to a network (such as a Long Term Evolution (LTE) network or an evolved universal mobile telephone system (UMTS) terrestrial radio access network (E-UTRAN)). In some examples, the NAS layer may be used to manage the establishment of communication sessions with a UE and for maintaining continuous communications with a UE as the UE moves. In some examples, network access may be provided when a UE transmits an attach request to the NAS layer. The NAS layer may respond by allowing the UE to attach to the network.
In some instances, network communications may be protected. Protected communications may include communications that contain private or confidential information. However, some types of network communications may lack protection or security. In particular, messages communicated before security algorithms have been agreed upon between a UE and a core network may lack adequate protection. As another example, messages for establishing communication may also lack adequate security. Unprotected NAS messages, and in particular, those used to attach a UE to a network, may be examples of such unprotected communications. Unprotected communications may be subject to exploitation by attackers, for example.